Effect of chordwise location of maximum thickness on the supersonic wave drag of sweptback wings

Abstract : On the basis of the linearized theory of supersonic flow, equations are derived for the wave drag of sweptback untapered wings at zero lift with thin double-wedge sections and arbitrary chordwise location of maximum thickness. Calculations are presented for a representative supersonic plan form. The optimum location of maximum thickness for untapered supersonic wings is found to be at 50 percent chord, a symmetrical variation in wing wave-drag coefficient being exhibited about this minimum value. The drag variation is slight when considerable sweep behind the Mach lines is present and the variation is marked at Mach numbers where the wing approaches or is swept ahead of the Mach lines. It is found that for tapered plan forms the sweep of the line of maximum thickness is an important sweep parameter insofar as drag due to thickness is concerned.